EG4 Community Forum - Recent Topics

Flexboss 21 - PV String Anomalies (Clipping) when under high load

vMAC — Mon, 15 Jun 2026 21:44:13 +0000

First I have a Flexboss 21 (FAAB-2525) that is installed in my garage along with two EG4 Indoor batteries, and PV strings (42, 410w panels) that come off the attic directly into my inverter (no combiner, disconnect, or breakers). I then have a 60 amp breaker that backfeeds into the main breaker box. So it supplies any excess solar to the main breaker to feed loads or back to my utility for buyback.

My issue is that if I have a high load (I don't know how long it has to be, but over 30 minutes based on the logs) the PV strings will stop growing in power. So if I am pulling in 4kw @ 8am off the panels, and the load stays over a certain threshold for longer than a certain amount of time, the PV will stop growing. Today I had this happen in which my AC is running nonstop (because it's going to be 111*) and my mini-split in the casita is doing the same, and pool pump etc are all running. Due to this the PV stopped growing at 3kw. I didn't notice it, so the batteries never charged today and it kept pulling from the Grid instead of resetting the PV strings. When I notice this happens my only solution (that I know of) is to restart the inverter entirely and it will then jump from 3kw to (in the case of today) 13kw immediately. I have provided the logs from today, and a screenshot from today, when this happened. I also had this happen while I was on vacation 6/1/26 and pulled the logs and snapshot of the same (you should see the spike in Solar PV from a low number to one much higher, the only change is a restart of the inverter.

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Can someone help me diagnose why this is happening, and how it can be fixed? I know I am not on the latest firmware, but when I seen the release notes, I didn't see anything in regards to this issue. It won't let me upload the excel from EG4 website, but if anyone needs it I can send.

Flexboss 21 - PV String Anomalies when under high load

vMAC — Mon, 15 Jun 2026 20:59:29 +0000

I'm hoping that someone on this forum can help me with a recurring/repeatable issue that I have been having with the Flexboss 21. I've called Signature Solar number times and they don't believe the unit is functioning out of spec. As this is a the second Flexboss 21 that I've had, I'd be extremely worried if both had this same rare issue. Here is a brief synopsis of the issue, and while I'm happy to share more information, I don't know how to put it into the best technical terms, so I will just explain what I'm seeing.

First I have a Flexboss 21 (FAAB-2525) that is installed in my garage along with two EG4 Indoor batteries, and PV strings (42, 410w panels) that come off the attic directly into my inverter (no combiner, disconnect, or breakers). I then have a 60 amp breaker that backfeeds into the main breaker box. So it supplies any excess solar to the main breaker to feed loads or back to my utility for buyback.

My issue is that if I have a high load (I don't know how long it has to be, but over 30 minutes based on the logs) the PV strings will stop growing in power. So if I am pulling in 4kw @ 8am off the panels, and the load stays over a certain threshold for longer than a certain amount of time, the PV will stop growing. Today I had this happen in which my AC is running nonstop (because it's going to be 111*) and my mini-split in the casita is doing the same, and pool pump etc are all running. Due to this the PV stopped growing at 3kw. I didn't notice it, so the batteries never charged today and it kept pulling from the Grid instead of resetting the PV strings. When I notice this happens my only solution (that I know of) is to restart the inverter entirely and it will then jump from 3kw to (in the case of today) 13kw immediately. I have provided the logs from today, and a screenshot from today, when this happened. I also had this happen while I was on vacation 6/1/26 and pulled the logs and snapshot of the same (you should see the spike in Solar PV from a low number to one much higher, the only change is a restart of the inverter.

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Can someone help me diagnose why this is happening, and how it can be fixed? I know I am not on the latest firmware, but when I seen the release notes, I didn't see anything in regards to this issue.

rs485 + hdmi + solar assistant -> cheap solution. 12000xp

clarktheshark — Mon, 08 Jun 2026 04:21:29 +0000

I havent had very good luck with the eg4 wifi dongles. I have to reset them every once in awhile which is annoying. also one of mine seems to only be able to update every couple of minutes which was causing silly readings in solar assistant.

I thought i should be able to hook directly to rs485 via usb converter using the HDMI pins.

a couple bucks on amazon for the hdmi repair pieces and the usb/rs485 converters and i was off to the races.

I ran the wires 50 feet (twisted pair) to the raspberry pi in the server closet. It works great. I get readings every 10 seconds flawlessly.

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Peak Shaving causing Solar Clipping

BobAndRoslyn — Sun, 07 Jun 2026 16:27:19 +0000

I had noticed after enabling peak shaving that solar input is being clipped severely (by half). When I turn peak shaving off, the clipping is eliminated. This seems like a bug. Can anyone else confirm this behavior?

Error W009 - fan stuck

GotTheKnack — Sat, 06 Jun 2026 15:25:25 +0000

FlexBoss21: Well, the fan is actually running, I slipped a small piece of paper up through the grill and it is indeed running, which leads me to believe that its a motion sensor issue. I can't determine determine if the problem is on a circuit board, or more likely in the fan, or a bad connection there. BUT, the fault light is always on and that could hide a more serious fault. So, I had better do something about it.

It appears that the fan array can be removed externally for inspection, tests, possible component replacement, etc if the Inverter is off and isolated electrically for safety purposes.

Is this fan tray available separately?
Can it be replaced "in place"?
What is the part number needed?

My system was purchased in late fall of 2025 and commissioned literally 2 hours before the end of the tax rebate expiration- kudos to all that helped me!

I have no experience with EG4 hardware support, RMA procedures, etc. So I need directions on how to proceed.

Items are all warranted under my name, the electrical contractor ordered from Soligent, by agreement with the electrical contractor, I am first line support for my system. I am experienced with heavy industrial electronics and electrical work by trade, but retired.

Allen

Is it possible to clear messages in 18kPV?

detschel — Sat, 06 Jun 2026 00:42:07 +0000

Hi, is there a way to clear the meassages / event log in the 18kPV? Setup includes two 280 indoor batteries if that matters. Thanks !

Help! - Had solar panels, EG4 Inverter and Batteries installed in 7/2026- Has never been right.

Dutch-34 — Wed, 03 Jun 2026 18:58:27 +0000

Hello. I’m new to the forum and I’m hoping it to get some guidance or direction on what to do about the Solar power system and storage that I had installed on my home almost a year ago. I have 42 Canadian Solar Panels with Enphase Micro Inverters, EG4 18 Inverter and three EG4 12kw Batteries. We have not been able to use the batteries at all without significant problems. When using we a getting significant surges in the home that dim all the lights associated with the backed up circuits, so much so that it causes the router in our home to lose power and reset and at times will power down our TV. This continues in cycles of appx 3 minutes repeatedly. There is also an unsettling electrical sound that occurs at the same time. This happens primarily at night, but sometimes during the day as well.

The installer has been out many, many times. They even replaced the inverter under warranty believing that is the problem. However that did not correct the issue. They changed the breaker and upgraded the wiring to the breaker, but no luck. I believe the installer has and is trying to correct the issue, but they have not been able to correct the problem in nearly a year. I honestly believe they do not know what to do to fix this, at this point.

So I have a very expensive system that does not work. The inverter has been throwing a “Bus Voltage High” fault repeatedly. I have since turned off the batteries at the breaker on the inverter to avoid damage to appliances and electronics. Also, for personal safety. This seems unsafe. Sorry for the long post, but I really dont know what to do at this point. Any help is much appreciated.

EG4 Monitor Dashboard missing detailed info

KingSolar — Wed, 03 Jun 2026 16:15:10 +0000

EG4 Demo Dashboard

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My Dashboard

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Problem with EG4 14.3kWh WALLMOUNT ALL WEATHER LITHIUM BATTERY with BMS off

DJIMELI Paulin — Wed, 03 Jun 2026 10:02:34 +0000

Good evening, I have a system with two EG4 14.3kWh WALLMOUNT ALL WEATHER LITHIUM BATTERIES with BMS. For over a month now, my system has stopped working, and after checking, I realized that the first battery is completely discharged, or at least the voltage across its terminals is 2.3V, while the second shows a full charge at 51.2V.
What caused this problem, and how can I reactivate the battery?

MPPT Production Change

Johnaand — Mon, 01 Jun 2026 23:25:39 +0000

I have a Flexboss21 Inverter with 28 solar panels connected to MPPT's 1,2 & 3. Up until today I have been getting great solar generation from all three MPPT's. I have attached the Ppv1,2 & 3 charts for yesterday (5/31) and today (6/1) and there is a definite change to MPPT's 1 & 2 that started about 9:38AM today. As you can see MPPT-3 does not appear to be affected. Looking for any help on what is going on.

Thanks,

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